man3/wcwidth.3

   1 .\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
   2 .\"
   3 .\" SPDX-License-Identifier: GPL-2.0-or-later
   4 .\"
   5 .\" References consulted:
   6 .\"   GNU glibc-2 source code and manual
   7 .\"   Dinkumware C library reference http://www.dinkumware.com/
   8 .\"   OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html
   9 .\"
  10 .TH wcwidth 3 (date) "Linux man-pages (unreleased)"
  11 .SH NAME
  12 wcwidth \- determine columns needed for a wide character
  13 .SH LIBRARY
  14 Standard C library
  15 .RI ( libc ", " \-lc )
  16 .SH SYNOPSIS
  17 .nf
  18 .BR "#define _XOPEN_SOURCE" "       /* See feature_test_macros(7) */"
  19 .B #include <wchar.h>
  20 .PP
  21 .BI "int wcwidth(wchar_t " c );
  22 .fi
  23 .SH DESCRIPTION
  24 The
  25 .BR wcwidth ()
  26 function returns the number of columns
  27 needed to represent the wide character
  28 .IR c .
  29 If
  30 .I c
  31 is a printable wide character, the value
  32 is at least 0.
  33 If
  34 .I c
  35 is null wide character (L\(aq\e0\(aq), the value is 0.
  36 Otherwise, \-1 is returned.
  37 .SH RETURN VALUE
  38 The
  39 .BR wcwidth ()
  40 function returns the number of
  41 column positions for
  42 .IR c .
  43 .SH ATTRIBUTES
  44 For an explanation of the terms used in this section, see
  45 .BR attributes (7).
  46 .ad l
  47 .nh
  48 .TS
  49 allbox;
  50 lbx lb lb
  51 l l l.
  52 Interface       Attribute       Value
  53 T{
  54 .BR wcwidth ()
  55 T}      Thread safety   MT-Safe locale
  56 .TE
  57 .hy
  58 .ad
  59 .sp 1
  60 .SH STANDARDS
  61 POSIX.1-2001, POSIX.1-2008.
  62 .PP
  63 Note that glibc before 2.2.5 used the prototype
  64 .PP
  65 .nf
  66 .BI "int wcwidth(wint_t " c );
  67 .fi
  68 .SH NOTES
  69 The behavior of
  70 .BR wcwidth ()
  71 depends on the
  72 .B LC_CTYPE
  73 category of the
  74 current locale.
  75 .SH SEE ALSO
  76 .BR iswprint (3),
  77 .BR wcswidth (3)